Introduction: New Zealand Ministry of Health guidelines1 recommend women with a history of gestational diabetes mellitus have a glycated haemoglobin (HbA1c) measured at 3 months postpartum to screen for the development of diabetes. The aims of this study were to assess adherence to this recommendation in a recent New Zealand cohort, and to assess if different glycaemic treatment targets during pregnancy affected this.
Methods: This was a cohort study of women from the TARGET trial2 who participated in the TARGET 4.5 Year Follow-Up study. HbA1c measurements were collected from laboratory results and general practice records. Adherence to the recommendation was defined as at least one HbA1c measurement in the period between the index birth and 9 months’ postpartum. The 95% confidence intervals and between group differences were calculated using an exact mid-P method or Students t-test.
Results: Overall, 169/315 (53.7%, 95% CI 48.1, 59.1) of women adhered to the recommended HbA1c screening postpartum. There was no difference in adherence between the tight target group and the less tight target group (95/163, 58.3% versus 74/152, 48.7%, risk difference 9.6%, 95% CI -1.38, 20.57, p=0.09). The mean time to first postpartum HbA1c was also similar between groups (4.6 months, SD 2.0 versus 4.3 months, SD 1.8, mean difference 0.35 months, 95% CI -0.24, 0.94, p=0.16).
Conclusions: Adherence to recommended postpartum HbA1c screening at 3 months was poor and was not affected by different glycaemic targets used during pregnancy.